Method for the termination of anionic polymerization by Lewis acid

Abstract

The present invention relates to a method for the termination of anionic polymerization by Lewis acid, more particularly, a method for terminating anionic polymerization by employing Lewis acid as a terminating agent to terminate terminally reactive group in the preparation of conjugated diene polymers so that the reaction may be terminated effectively without further couplings, there is no color fading, and it does not require additional neutralization process and a controlling process of pH since any basic product, which reacts with an antioxidant, is not produced.

Description

FILED OF THE INVENTION

[0001] The present invention relates to a method for the termination of anionic polymerization by Lewis acid, more particularly, a method for terminating anionic polymerization by employing Lewis acid as a terminating agent to terminate a terminally reactive end group in the preparation of conjugated diene polymers so that the reaction is terminated efficiently without further couplings, there is no discoloration, and it does not require additional processes of neutralization and pH adjustment because there is no basic product produced, which may react with an antioxidant.

[0002] Generally, homopolymers prepared by polymerization of conjugated diene monomers such as butadiene and isoprene, styrene-conjugated diene copolymers prepared by copolymerization of styrenes and conjugated dienes, or block copolymers such as styrene-butadiene-styrene(SBS) block copolymer and styrene-isoprene-styrene(SIS) block copolymer prepared by block polymerization of blocks with an...

Examples

example 1

Termination of the Polymerization of Styrene-Butadiene Block Copolymer Using Triethyl Aluminum

[0033] A 2L reactor was charged with Argon gas. 900 g of cyclohexane, 0.2 ml of tetrahydrofuran, and 40 g of styrene were placed thereto. The reaction solution was heated to a temperature of 50° C. 2 mmol of n-butyl lithium(1.3M cyclohexane solution) of an initiator was added to the reaction solution. 10 min later after the temperature of the polymerization reached highest, 120 g of butadiene was added to the reaction solution. 5 min later after the temperature of the polymerization of butadiene reached highest, 2 mmol of triethyl aluminum was added to the reaction solution to remove reactive living polymers. Then an antioxidant was added. After the polymerization was completed, 5 g of styrene was additionally added to observe the degree of removing reactive living polymers. The solvent was removed by employing steam stripping from resulting polymer solution to obtain styrene-butadiene blo...

example 2

Termination of the Polymerization of Butadienes Using Triisobutyl Aluminum Hydride

[0034] A 2L reactor was charged with Argon gas. 900 g of cyclohexane, 0.2 ml of tetrahydrofuran, and 175 g of butadiene were placed thereto. The reaction solution was heated to a temperature of 50° C. 2 mmol of n-butyl lithium(1.3M cyclohexane solution) of an initiator was added to the reaction solution. 5 min later after the temperature of the polymerization reached highest, 2 mmol of trisobutyl aluminum hydride was added to the reaction solution to remove reactive living polymers. Then an antioxidant was added. After the polymerization was completed, 5 g of styrene was additionally added to observe the degree of removing reactive living polymers. The solvent was removed by employing steam stripping from the resulting polymer solution, roll milled and further dried to obtain polybutadiene.

example 3

Termination of the Polymerization of Butadiene Using Triethyl Borane

[0035] A 2L reactor was charged with Argon gas. 900 g of cyclohexane, 0.2 ml of tetrahydrofuran, and 175 g of butadiene were placed thereto. The reaction solution was heated to a temperature of 50° C. 2 mmol of n-butyl lithium(1.3M cyclohexane solution) of an initiator was added to the reaction solution. 5 min later after the temperature of the polymerization reached highest, 2 mmol of triethyl borane was added to the reaction solution to remove reactive living polymers. Then an antioxidant was added. After the polymerization was completed, 5 g of styrene was additionally added to observe the degree of removing reactive living polymers. The solvent was removed by employing steam stripping from the resulting polymer solution, roll milled and further dried to obtain polybutadiene.

FILED OF THE INVENTION

[0001] The present invention relates to a method for the termination of anionic polymerization by Lewis acid, more particularly, a method for terminating anionic polymerization by employing Lewis acid as a terminating agent to terminate a terminally reactive end group in the preparation of conjugated diene polymers so that the reaction is terminated efficiently without further couplings, there is no discoloration, and it does not require additional processes of neutralization and pH adjustment because there is no basic product produced, which may react with an antioxidant.

[0002] Generally, homopolymers prepared by polymerization of conjugated diene monomers such as butadiene and isoprene, styrene-conjugated diene copolymers prepared by copolymerization of styrenes and conjugated dienes, or block copolymers such as styrene-butadiene-styrene(SBS) block copolymer and styrene-isoprene-styrene(SIS) block copolymer prepared by block polymerization of blocks with an...

Examples

example 1

Termination of the Polymerization of Styrene-Butadiene Block Copolymer Using Triethyl Aluminum

[0033] A 2L reactor was charged with Argon gas. 900 g of cyclohexane, 0.2 ml of tetrahydrofuran, and 40 g of styrene were placed thereto. The reaction solution was heated to a temperature of 50° C. 2 mmol of n-butyl lithium(1.3M cyclohexane solution) of an initiator was added to the reaction solution. 10 min later after the temperature of the polymerization reached highest, 120 g of butadiene was added to the reaction solution. 5 min later after the temperature of the polymerization of butadiene reached highest, 2 mmol of triethyl aluminum was added to the reaction solution to remove reactive living polymers. Then an antioxidant was added. After the polymerization was completed, 5 g of styrene was additionally added to observe the degree of removing reactive living polymers. The solvent was removed by employing steam stripping from resulting polymer solution to obtain styrene-butadiene blo...

example 2

Termination of the Polymerization of Butadienes Using Triisobutyl Aluminum Hydride

[0034] A 2L reactor was charged with Argon gas. 900 g of cyclohexane, 0.2 ml of tetrahydrofuran, and 175 g of butadiene were placed thereto. The reaction solution was heated to a temperature of 50° C. 2 mmol of n-butyl lithium(1.3M cyclohexane solution) of an initiator was added to the reaction solution. 5 min later after the temperature of the polymerization reached highest, 2 mmol of trisobutyl aluminum hydride was added to the reaction solution to remove reactive living polymers. Then an antioxidant was added. After the polymerization was completed, 5 g of styrene was additionally added to observe the degree of removing reactive living polymers. The solvent was removed by employing steam stripping from the resulting polymer solution, roll milled and further dried to obtain polybutadiene.

example 3

Termination of the Polymerization of Butadiene Using Triethyl Borane

[0035] A 2L reactor was charged with Argon gas. 900 g of cyclohexane, 0.2 ml of tetrahydrofuran, and 175 g of butadiene were placed thereto. The reaction solution was heated to a temperature of 50° C. 2 mmol of n-butyl lithium(1.3M cyclohexane solution) of an initiator was added to the reaction solution. 5 min later after the temperature of the polymerization reached highest, 2 mmol of triethyl borane was added to the reaction solution to remove reactive living polymers. Then an antioxidant was added. After the polymerization was completed, 5 g of styrene was additionally added to observe the degree of removing reactive living polymers. The solvent was removed by employing steam stripping from the resulting polymer solution, roll milled and further dried to obtain polybutadiene.